Lesson 4 Menu
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1. Find the surface area of a cylinder with r = 10 and h = 6. Round to the nearest tenth. 2. Find the surface area of a cylinder with r = 4.5 and h = 6.3. Round to the nearest tenth. 3. Find the surface area of the cylinder shown to the nearest tenth. 4. What is the height of a cylinder with radius of 4 centimeters and surface area of 80 square centimeters?
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Find the surface area of a cylinder with r = 10 and h = 6. Round to the nearest tenth. Find the surface area of a cylinder with r = 4.5 and h = 6.3. Round to the nearest tenth. 3.Find the surface area of the cylinder shown to the nearest tenth. - PowerPoint PPT Presentation
Transcript of Lesson 4 Menu
1. Find the surface area of a cylinder with r = 10 and h = 6. Round to the nearest tenth.
2. Find the surface area of a cylinder with r = 4.5 and
h = 6.3. Round to the nearest tenth.
3. Find the surface area of the cylinder
shown to the nearest tenth.
4. What is the height of a cylinder with
radius of 4 centimeters and surface
area of 80 square centimeters?
• regular pyramid
• slant height
• Find lateral areas of regular pyramids.
• Find surface areas of regular pyramids.
CANDLES A candle store offers a pyramidal candle that burns for 20 hours. The square base is 6 centimeters on a side and the slant height of the candle is 22 centimeters. Find the lateral area of the candle.
Find Lateral Area
We need to find the lateral area of the square pyramid. The sides of the base measure 6 centimeters, so the perimeter is
Answer: The lateral area of the candle is 264 square centimeters.
Find Lateral Area
Lateral area of a regular pyramid
Multiply.
A. A
B. B
C. C
D. D
A. 25.9 ft2
B. 51.8 ft2
C. 103.6 ft2
D. 207.2 ft2
CAMPING A tent in the shape of a pyramid is put up by two campers. The square base is 7 feet on a side and the slant height of the tent is 7.4 feet. Find the lateral area of the tent.
Surface Area of a Square Pyramid
Find the surface area of the square pyramid. Round to the nearest tenth if necessary.
To find the surface area, first find the slant height of the pyramid. The slant height is the hypotenuse of a right triangle with legs that are the altitude and a segment with a length that is one-half the side measure of the base.
Surface Area of a Square Pyramid
Pythagorean Theorem
Simplify.
Now find the surface area of a square pyramid. The perimeter of the base is and the area of the base is
Surface Area of a Square Pyramid
Answer: The surface area is 179.4 square meters to the nearest tenth.
Use a calculator.
Surface area of a square pyramid
1. A
2. B
3. C
4. D
A. 73.8 m2
B. 89.8 m2
C. 163.5 m2
D. 696 m2
Find the surface area of the square pyramid to the nearest tenth.
Surface Area of a Regular Pyramid
Find the surface area of the regular pyramid. Round to the nearest tenth.
The altitude, slant height, and apothem form a right triangle. Use the Pythagorean Theorem to find the apothem. Let x represent the length of the apothem.
Surface Area of a Regular Pyramid
Pythagorean Theorem
Simplify.
Now find the length of the sides of the base. The central
angle of the hexagon measures Let a
represent the measure of the angle formed by a radius
and the apothem.
Surface Area of a Regular Pyramid
Use trigonometry to find the length of the sides.
Multiply each side by 2.
Multiply each side by 9.
Use a calculator.
Surface Area of a Regular Pyramid
Next, find the perimeter and area of the base.
Surface Area of a Regular Pyramid
Finally, find the surface area.
Answer: The surface area is approximately 748.2 square centimeters.
Surface area of a regular pyramid
Simplify.
1. A
2. B
3. C
4. D
A. 236.1 cm2
B. 326.9 cm2
C. 90.8 cm2
D. 417.7 cm2
Find the surface area of the regular pentagonal pyramid.
